1. Field of the Invention
This invention relates to a cleaning device for use in an image forming apparatus such as a copying apparatus, a laser beam printer or a micro instrument, and particularly to a cleaning device in which a cleaning blade is sandwiched between sandwiching members and the cleaning blade and the sandwiching members are coupled together by the tightening force of screws or the like.
2. Description of the Prior Art
Description will hereinafter be made by taking as an example a cleaning device used in an electrophotographic copying apparatus.
In various types of image forming apparatus wherein a developed image is formed on an image bearing member such as an electrophotographic photosensitive member or the like and transferred to a transfer medium, an elastic cleaning blade has been widely used as a device for cleaning the image bearing member after the image transfer.
In such blade type cleaning device, the elastic cleaning blade is sandwiched by a holder provided with sandwiching members such as iron plates and this is mounted to the body of a copying apparatus or the like, whereby cleaning is effected.
Now, when the cleaning blade is sandwiched between the sandwiching members such as iron plates, it has been practised to apply the sandwiching members to the front and back sides of the blade and tightening these three members at a plurality of locations by the use of screws, thereby coupling them together.
This system has the advantages that reliable coupling can be easily accomplished and that replacement of the blade can be readily accomplished.
However, the tightening force is provided from the tightened point of the sandwiching members and therefore, where the sandwiching members are not of a sufficient thickness and strength or where the distance from the tightened point to the portion sandwiching the elastic cleaning blade is short, the elastic cleaning blade is sometimes sandwiched in its waving condition. This may cause unsatisfactory cleaning or rapid loss of the blade. For this reason, in the conventional devices, the sandwiching members such as iron plates have been made to have a sufficient thickness and size. Further, in some cases, it has been necessary to provide the simple plate-like members with a complicated reinforcing portion.
Such conventional construction has been a hindrance to compactness and light weight of the cleaning device and further, of the image forming apparatus.